Could I be pregnant.

Hi I'm  26 years  old.  My. Husband  and  I  have been  trying to  get pregnant  with our  2 child for a year now. Without  any luck. I one of these type of women who don't  miss a period  and my period  are always  on time. Expect  for this time I was suppose to start my period  on Feb 23, 2017. I still haven't  started my period  yet. I have already  taken a clear blue pregnancy test, but it came back negative. The last time I missed my period  was December of  2014 when I got pregnant  with  my daughter. What should  I  do  please help.